The word "ecology" was firstly used by the German biologist E. Haeckel in 1866. It comes from two Greek words: Oikós (which
means "house") and Logos (which means "study"). Ecology means Science of the Habitat. It studies the conditions in which living beings survive, as well as their environment. A concept which is common to most people is that no organism (whether it is a bacteria, a fungus, a tree, a worm, an insect, an animal or a human being) exists without interacting. We often practice ecology without noticing it. Modern ecology was born on the 1930's. An
ecossystem has got both physical and living elements. In an ecossystem, the physical and living elements exist together in the same area, living on a dependence process. We can consider the whole Universe as an ecossystem. Some
ecossystems are destroied and endangered, along with the animals that inhabit them. Deforestation causes important climate changes. Ecology teaches that the preservation of the species and the ecossystems is one of the most important issues in Nature Conservation. Any garden is a rich environment, concerning life forms. Worried with the destruction of ecossystems, UNESCO has created the concept of biosphere reserves. Mata Atlântica (Atlantic Forest) is considered one of the most threatened ecossystems of the planet. Its protection is essencial. Some of the impacts that the Amazon Ecossystems suffers are: deforestation, greenhouse effect, gold mining, roads, aliminium and iron industry, large hidroelectric stations, predatory fishing and hunting and exploitationg of populations. The area of Paraguai river has got one of the biggest turistic potencial and is where the biggest floods in the world occur. It occupies a large area and has got rich populations of fish, birds and mammals. Each citizen should do his part, preserving Nature, keeping his town and house clean, taking care of his animals.